The 57-year-old Keaton wishes she had seized the day in the late 1970s, after her Oscar win for "Annie Hall," and done what last year's best-actress recipient Kidman is doing now: Going for broke with a wild variety of roles.

"I think that she's a very brave movie star," Keaton said of Kidman, who has been on a tear with her Oscar win in "The Hours," the musical "Moulin Rouge," the horror hit "The Others" and a rush of other films, including the upcoming "Cold Mountain."

"I love her spirit. I think she knows that nothing can defeat her. She's just a brave warrior," Keaton told The Associated Press over lunch at the swanky Beverly Hills Hotel. "And I wasn't that way. I don't think I was adventurous enough. I think I should have just flung myself out there. I was scared, I was cautious, I was careful, I was afraid. I felt insecure. And so a lot of time went by, and I didn't do enough work.

"That's my opinion of how I managed my one, big successful moment."

Strangely self-deprecating, considering everything that's come Keaton's way since her early successes in "The Godfather" saga, "Looking for Mr. Goodbar," and "Annie Hall" and other Woody Allen movies.

Keaton scored Oscar nominations for "Reds" and "Marvin's Room," had hits with "Baby Boom," "The First Wives Club" and the "Father of the Bride" movies and embarked on a career acting and directing for television.

Now she's at the center of a love triangle unique in youth-minded Hollywood, playing a 55-year-old divorced playwright pursued by a 63-year-old womanizer and a sensitive young doctor in the romantic comedy "Something's Gotta Give."

Jack Nicholson plays Harry Sanborn, a wealthy cad who has never dated a woman older than 30. On a weekend getaway with his current trophy girlfriend (Amanda Peet) he has a heart attack and is forced to recuperate at the beach house of his lover's mother, Erica Barry (Keaton). Harry ends up falling for Erica, fighting for her affections with his 30-something emergency-room doctor (Keanu Reeves).

Early on, Erica Barry is a woman who figures her romantic days are long past, sentiments Keaton shares in her own life.

Keaton, whose past romantic partners included Allen and Warren Beatty, said she has given up on love. Other things, including her adopted 7-year-old daughter and 2-year-old son, have moved in to replace romance.

"I feel like I've been in love, but I don't really want to go back there again," Keaton said. "I don't really want to experience any of it at all if it's going to cause me what love did for me before. Thank you very much, count me out. ...

"And I also realize that I wasn't my best self in my romantic alliances with men. I was always lost in the fantasy of it, and I don't think that made me happy. Even when I was at the happiest of that happiness, it was just fraught with anxiety."

Director Nancy Meyers ("What Women Want") wrote "Something's Gotta Give" specifically for Keaton, saying the actress embodies the grace, charm and sex appeal needed in an older woman who might turn the head of a lifelong cradle-robber like Harry.

"Diane's just luminous. She has this sparkling presence that hasn't gone away. She hasn't Botoxed and injected herself and siliconed herself into some kind of weird creature," co-star Peet said. "She looks fantastic, and then there's that whole adorable thing she still has going. If I were Keanu, I'd follow her around, too."

Though playing a successful writer in "Something's Gotta Give," Keaton manages to infuse the character with traces of the jittery, girlish goofiness that made Annie Hall so endearing.

"The goofy part is one of the greatest parts about Diane. Those arms flailing a little longer than you expect them to be," said Meyers, who co-wrote "Baby Boom" and the "Father of the Bride" movies. "Her eyes are sad, her smile's happy. Her face registers every emotion, sometimes all in one take. Diane's an absolute original. There was nobody like her before, and if there's been anybody like her since, they'll say she's 'Keaton-esque."'

Keaton's first success came with the 1968 Broadway musical "Hair," for which she was one of the few cast members who declined to strip naked for the play's finale. With "Something's Gotta Give," Keaton bares it all in a brief nude scene when Nicholson's character stumbles on her getting ready for bed.

On "Hair," Keaton did not see the point of stripping down. This time, the nudity was essential to the story, she said.

"With this, I felt entirely different," Keaton said. "A lot of time had passed, my relationship with my body has changed. I thought it was in the service of a good joke, but beyond that ... This is what the movie is about, that intimacy. An intimate, quick look at a woman of a certain age. Fine. There was no question I knew I was going to do it, I knew I wasn't going to fight it.

"So, you know, things change. And the fact that my body functions is what I'm really thrilled with now."

A Los Angeles native, Keaton knew from an early age that she wanted to be a performer. When she was 9, Keaton saw her mother win a local talent and beauty pageant and felt herself hooked.

"I was sitting in the audience watching my mother up there, and they put a crown on her. I remember just thinking, 'OK, that's it for me. That's where I want to be.' I was filled with anxiety, which meant it was always a push-pull thing with me, but I really, really wanted to be on stage."

Keaton did plays and studied drama in college but dropped out and moved to New York to pursue an acting career. After "Hair," she was cast in Allen's stage comedy "Play It Again, Sam," a role she reprised in the 1972 movie version.

Allen and Keaton's collaboration produced such films as "Sleeper," "Love and Death" and "Manhattan." They parted friends and reunited on screen for 1993's "Manhattan Murder Mystery," with Keaton stepping in after Allen's breakup from Mia Farrow.

Keaton's career has been spotty the last 20 years, with successes like "The First Wives Club" and "Baby Boom" offset by such flops as "The Little Drummer Girl," "The Lemon Sisters" and "Town & Country."

Her directing career - which began in 1987 with "Heaven," an offbeat chronicle of people's conceptions of the afterlife - also has been fitful. After directing episodes of "China Beach" and "Twin Peaks," Keaton made the acclaimed TV movie "Wildflower," with Reese Witherspoon.

The last feature film Keaton directed - "Hanging Up," in which she co-starred with Walter Matthau, Meg Ryan and Lisa Kudrow - flopped, hindering her efforts to raise money for other projects.

For Keaton, though, the past is the past. She shrugs off her failures and downplays her triumphs. "Annie Hall" and other Allen comedies that made her the epitome of romantic angst for a generation of movie lovers are ancient history, Keaton said.

"Those movies were quite awhile ago, and I think you can say many of them have been forgotten for most people. Because most people, unless they're my age or a little bit younger, it's just not something that they follow," Keaton said.

"I sort of basically feel that that has gone. It's over. But it gave me all these wonderful opportunities. And I'm sure that some people will always think of me as Annie Hall. Fine by me. I'm happy that they think of me at all."